Non-skid attachment for the ground-engaging end of canes,crutches,and the like



w. STARK 3,448,749

CRUTCHES AND THE LIKE Sheet of m x M m z 4 i m m f m a/ W W W I m A 2 M M 6 2 A m flwwxwwx s k X M. 6 fl ww I m x 0 w as c z za a 7 i v fi iwxtflfifi 5 2 6 a .wm a 3 "CANES June 10, 1969 NON-SKID ATTACHMENT FOR THE GROUND-ENGAGING END OF Filed May 22, 1968 June 10, 1969 Filed May 22. 1968 STARK 3,448,749

NON-SKID ATTACHMENT FOR THE GROUND-ENGAGING END OF CANES; CRUTCHES, AND THE LIKE sheet ,2 or 2" I NVENTOR ATTORNEYS Mada/W United States Patent 3,448,749 NON-SKID ATTACHMENT FOR THE GROUND- ENGAGING END OF CANES, CRUTCHES, AND THE LIKE Walter Stark, Rte. 2, Milaca, Minn. 56353 Filed May 22, 1968, Ser. No. 731,067 Int. Cl. A61h 3/02; A45b 9/04 US. Cl. 135-53 9 Claims ABSTRACT OF THE DISCLOSURE Background of the invention This invention relates to the general field of walking aids for persons suffering an impediment which impairs their ambulation, and comprises an improvement over the invention disclosed in my co-pending patent application filed April 27, 1967, Serial No. 634,219 now Patent No. 3,376,880 and bearing the title N'on-skid Attachment for the Ground-Engaging End of Canes, Crutches and the Like.

Walking aids of the type to which this invention generally pertains are old and well known in the art. Aids of this general description are conventionally formed of wood or of a light-weight metallic material to render the aid more maneuverable and with the expenditure of smaller amounts of energy on the part of the user. The ground-engaging ends of the conventional cane or crutch are generally provided with some type of friction device to prevent the ground-engaging end of the cane or crutch from skidding when the weight of the user is shifted or transferred to the aid. The prior art discloses that many of the conventional non-skid devices take the form of a button constructed of rubber or of other suitable material and is usually fixedly secured to the ground-engaging end of a cane by means conventional in the art. The prior art will also show that it is commonplace to encase the groundengaging end of a walking aid within a flexible rubber cap. Such non-skid means are generally sufficient, within limitations imposed thereon by their inherent construction, to serve their intended purpose and function, however, such devices become unreliable and generally fail or become totally useless for all practical purposes when inclement weather conditions are encountered, especially under conditions of snow and ice.

The prior art discloses attempts by several patentees to provide a walking aid to enable the user to walk about under such adverse weather conditions but, for the most part, such devices are unreliable in serving their intended function and purpose, are complex in construction thereby creating high manufacturing costs which, in turn, place such aids out of the financial reach of many handicapped persons, and such prior art structures generally require frequent inspection to determine if they are safe to be employed, and much maintenance is usually required.

Generalizing with respect to the known prior art devices of the type related to this invention, few are known wherein there is built into the ground-engaging end of the cane a swivelly mounted anti-skid attachment. Such attachments are of material assistance to the user of the aid in 3,448,749 Patented June 10, 1969 that having once positioned the aid on the ground or other supporting surface, the user may turn freely about the vertical axis of the cane or crutch without having to re-position the same at intervals as the turn is completed. This is an important safety factor and comprises one of the more salient features of the present invention.

While it has been stated above that some attachments have been provided for canes or crutches which will enable the user to pivot without re-positioning the cane, such prior art devices are usually of the rubber button or rubber sleeve type, but the art appears to be devoid of showings wherein the swivel or turning movement is pro vided in a single attachment adapted for use under fair as well as inclement weather conditions.

Accordingly, it is one of the primary objects of this invention to provide an anti-skid attachment or device for the ground-engaging ends of canes, crutches and related devices, the anti-skid attachment being of a type which is adapted to penetrate a ground surface or to engage thereagainst together with means permitting the free rotation of the main body portion of the cane, crutch or the like to rotate relative to the attachment.

Another object of this invention is to provide an attachment of the type generally referred to above wherein the attachment includes in combination, a non-skid friction element adapted to make surface contact with a supporting or ground surface and, selectively, to provide means in the nature of ground surface penetrating means available when conditions of ice or other slippery ground surfaces are encountered, and wherein the actuating means for the ground surface penetrating means is conveniently located immediately adjacent the handle means of the walking aid.

Still a further object of this invention is to provide an attachment for the ground-engaging ends of canes, crutches and the like wherein the attachment includes spike means to penetrate a ground surface, means for selectively and adjustably moving the spike means axially of the cane or crutch, and means for securing the spike means in its adjusted position.

Still another object of this invention is to provide an attachment for the ground-engaging end of canes and crutches, the attachment including a flexible groundengaging friction member employed at times when the ground surface is dry, spike means axially adjustable relative to the cane or crutch for extension or retraction through the flexible member when inclement weather conditions are encountered, and wherein the flexible ground-engaging friction member and the spike means are both mounted for simultaneous rotation about the longitudinal axis of the cane or crutch and throughout an arc of 360.

The present invention contemplates, as a still further object thereof, the provision of means of the type to which reference has been generally made supra, and wherein such means are noncomplex in construction and assembly, inexpensive to manufacture, and which are rugged and durable in use.

Other and further objects and advantages of the instant invention will become more manifest from a consideration of the following specification when read in conjunction with the annexed drawings.

Specification of the attachment of this invention and with the spike means extended to their operative positions in the manner shown in FIGURE 1;

FIGURE 3 is a detail transverse cross-sectional view, FIGURE 3 being taken substantially on the horizontal plane of line 3-3 of FIGURE 2, looking in the direction of the arrows;

FIGURE 4 is a bottom plan view of the attachment;

FIGURE 5 is a side elevation view of a crutch includ- =ing the attachment of this invention and showing the ground-engaging spikes in their extended operative positions;

FIGURE 6 is an enlarged fragmentary side elevational view illustrating details of means for locking the spike means in an adjusted position relative to the main body of the crutch;

FIGURE 7 is a detail transverse cross-sectional view, FIGURE 7 being taken substantially on the horizontal plane of line 7-7 of FIGURE 6, looking in the direction of the arrows; and

FIGURE 8 is a fragmentary detail cross-sectional view, FIGURE 8 being taken substantially on the vertical plane of line 88 of FIGURE 6, looking in the direction of the arrows.

Thus, and with specific reference to that embodiment of this invention as is illustrated in FIGURES 1 to 4, inclusive, reference numeral 10 designates, in general, a cane constructed in accordance with the teachings of one embodiment of this invention. The cane '10 is seen to include an elongated substantially hollow cylindrical and normally upright main body portion to the lower end of which is connected the ground-engaging attachment 14 with which this invention is immediately concerned. As is seen in FIGURE 2 of the drawings, the main body portion 12 is provided with a pair of opposed open ends of which the lowermost one thereof, reference being had to FIGURES l and 2, telescopically receives for rotation therein the elongated substantially cylindrical neck 16 of a ground-engaging attachment fitting assigned the general reference numeral 18. As is seen in FIGURE 2 of the drawings, the neck 16, intermediate the ends thereof is formed with an outwardly opening continuous U-shaped circumferential groove 20. Threaded into the main body portion 12 through suitable tapped openings, is a pair of diametrically opposed retainer screws 22 which loosely engage within the groove 20. The screws 22 cooperate with the groove to prevent inadvertent or accidental shifting of the fitting 18 axially with respect to the main body portion 12.

The lower end of the neck 16 is integrally connected with the upper end of an enlarged cylindrical housing 24, and substantially at the line of junction between the lower end of the neck 16 and the upper end of the housing 24 there is formed a circumferential shoulder 26 normally disposed in abutting relationship with respect to the lower end of the main body portion 12. The arrangement is such as to provide limiting means whereby the user is always assured that upon the introduction of the neck 16 into the main body portion 12, the groove 20 will always be disposed in confronting relationship relative to the screws 22.

The lower end of the housing 24 is formed with an enlarged downwardly opening substantially hollow cylindrical chamber 28 bounded and defined by the lower or inner end wall 30 of the shoulder 26 and a depending substantially hollow cylindrical side wall 32 integrally connected at its upper end with the shoulder 26 but having an outside diameter less than the outside diameter of the shoulder. A substantially smooth cylindrical bore 34 extends transversely through the neck 16 and the shoulder 26 and is in open communication at its inner end with the inner end of the cylindrical chamber 28, and the two are coaxially aligned, one with respect to the other.

Reference numeral 36 denotes an elongated substantially hollow tubular and cylindrical shaft which is mounted for reciprocation within the bore 34. As is seen in FIGURE 2 of the drawings, one end of the shaft 36 normally projects beyond the outer end of the neck 16, and the opposed end of the shaft 36 normally extends into the chamber 28. The last mentioned end of the shaft 36 abuts against the upper end 38 of a substantially solid cylindrical carrier plug 40, and the carrier plug 40 is centrally and transversely bored and counterbored at 42, 44, respectively, to receive a screw 46, the latter being threadedly received within the adjacent lower end of the shaft 36 to thereby releasably connect the carrier plug 40 to the shaft. It should be here noted that the bore 42 and its associated counterbore 44 are smooth whereby the carrier plug 40 is free to rotate about the axis of the screw 46. As is seen in FIGURE 2 of the drawings, the carrier plug 40 is telescopically received Within the chamber 28 and is reciprocable therein in accordance with the reciprocable motion of the shaft 36. One of the ends of a plurality of elongated substantially cylindrical spikes 48 are embedded or otherwise fixedly secured on the carrier plug 40, the other ends of the spikes 48 project laterally away from the lower end of the carrier plub 40 adjacent the circumferential marginal edge thereof. As is seen in FIGURE 2 of the drawings, the longitudinal axes of the spikes 48 extend in spaced but parallel relationship relative to the vertical axis of the carrier plug 40. Preferably, the spikes 48 are disposed in circumferentially spaced relationship relative to one another and the outer free ends of each are sharpened or pointed as at 50.

A substantially hollow elongated cylindrical closure cap is designated by reference numeral 52. The closure cap 52 comprises an elongated substantially cylindrical internally threaded side wall 54 which is adapted to be threaded on the external side of the side wall 32, and the lower end of the closure cap 52 as viewed in FIGURE 2 is seen to be closed by an end wall 56. The end wall 56 is formed with a plurality of transversely extending circumferentially spaced openings 58 which receive the spikes 48 for reciprocation therethrough. Preferably, the outside diameter of the side wall 54 is substantially identical to the outside diameter of the shoulder 26, and the axial length of the side wall 54 is such that upon being fully threaded on the side wall 32 the upper end of the side wall 54 abuts the underside of the shoulder 26 while substantially simultaneously therewith, the lower end of the side wall 32 abuts against the adjacent side of the end wall 56.

- Reference numeral 60 denotes a substantially frustoconical ground-engaging cap having a substantially hollow cylindrical axially extending bore 62 formed therein, the bore 62 opening outwardly substantially in the plane of its frustum. The lower end of the bore 62 is closed by an end wall 64, and the end wall 64 is provided with a plurality of transversely extending circumferentially spaced openings 66 corresponding in number to the number of openings 58 and spikes 48. As is seen in FIG- URE 2, the closure cap 52 is adapted to be substantially entirely received within the bore 62 with the groundengaging cap 60 frictionally adhering thereto. The arrangement is such that the openings 66 are coaxially aligned with the openings 58 whereby the spikes 48 may also be reciprocated through the openings 66, and the spikes 48 are, of course, of such length as to project beyond the lower or base end of the ground-engaging cap 60 when moved to their respective operative positions.

The upper end of the shaft 36 is internally threaded to receive the threaded lower end 68 of an elongated substantially cylindrical second shaft 70. The threaded end 68 receives thereon an adjustment and locking nut 72 to which further reference will be made below. The axial length of the second shaft 70 is sufficiently great so as to permit the other or upper end thereof to project an appreciable distance beyond the first mentioned end of the main body portion 12 to serve a function to be described. It should be here noted, however, that the second shaft 70 is formed of a suitable metallic material having some degree of flexibility, and that the shaft 70 is constructed with an outside diameter appreciably smaller than the inside diameter of the main body portion 12 whereby the shaft 70' is afforded some freedom in movement in moving between an unflexed and flexed position.

Reference numeral 74 designates an elongated substantially cylindrical connector element having a centrally located cylindrical main body portion 76. The opposed ends of the main body portion 76 are essentially frustoconical in configuration and are identified by reference numerals 78, 80, respectively. As is seen in FIGURE 2, the frusto-conical ends 78, 80 taper in directions away from one another and that the end 78 is bored and counterbored at 82, 84, respectively, to form an internally located annular abutment shoulder 86. The first mentioned end of the main body portion 12, or the upper end thereof as viewed in FIGURE 2, is inserted within the counterborse 84 until the upper free end of the main body portion 12 abuts against the shoulder 86. The relative positions of the main body portion 12 and the end 78 may be maintained fixed by a conventional means such as the set screws 88. The inner end of the bore 82 is in open communication 'with one end of an elongated substantially rectangular pocket 90. The pocket 90 is elongated in the direction of the longitudinal axis of the main body portion 76 and opens through a side thereof.

A pivot pin 92 extends transversely across the pocket 90 in a direction perpendicular to thelongitudinal axis of the connector element 74 and supports a disk 94 for pivotal movement within the pocket 90. As is seen in FIGURE 2 of the drawings, the normally horizontal axis of the pivot pin '92 is laterally displaced from the normally vertically extending longitudinal axis of the main body portion 12, and the disk 94 is of such diameter as to cause a portion thereof to'project through the open side of the chamber 90. The disk 94, at the circumferential edge 95 thereof, is provided with an inwardly extending slot 96 of U-shaped configuration and being defined by a pair of opposed side walls 98, 100 and a bight 102 which extends on a cord of the disk 94. The disk is also formed with a socket 104 (see FIGURE 2) which extends inwardly from the bight 102 adjacent an end thereof. A second pivot pin 106 has its opposed ends supported on the side walls 98, 100 adjacent the outer circumferential marginal edge thereof, the pivot pin 106 spanning the slot 96 and being disposed in confronting relationship relative to the socket 104. The pivot pin 106 extends diametrically through the upper end of the shaft 70 to.

pivotally connect that end of the shaft 70 with the disk 94. As will be seen from inspection of FIGURE 2 of the drawings, the socket 104 provides clearance for the upper end of the shaft 70 when the component elements of this invention are in their respective positions as shown in this figure, and that the axis of the shaft 92 and that of the pin 106 are on a virtual dead center.

Reference numeral 108 indicates a digital operated actuating lever here illustrated as being a hex-shaped eyebolt having an enlarged hexagonal head 110 through which transversely extends a substantially cylindrical finger-receiving opening 112. From the edge 114 of the head 110 laterally projects an externally threaded shank 116 which is threaded into the radially extending tapped opening 118 formed in the disk 94.

The lever 108 is operable to two positions, namely, a first position as is shown in FIGURE 2 wherein the spikes 48 are extended beyond the cap 60 or to a second position (not shown) wherein the lever 108 is pivoted downwardly, in a clockwise direction with reference to this figure, into juxtaposition relative to the frusto-conical end 78. In the latter position the spikes 48 are retracted within the end 7 8.

Means is provided to releasably secure the lever in either of its two positions, and these means comprise an elongated leaf spring 119 disposed in the pocket 90 and having an end 119A thereof fixedly secured therein and to the main body portion 76 as by rivets 119B or by other well known and conventional means. The other end 119C is curved about an adjacent peripheral edge portion of the disk '94 to underlie the adjacent inner end of the end portion of the connector element 74. As is seen in FIGURE 2, the aforementioned other end 1190 is provided with detent means 119D which is selectively engageable within either of the circumferentially spaced recesses 95A, 953 formed in the peripheral edge 95 of the disk 94.

The free end 1190 of the spring 119 is biased for movement away from the peripheral edge 95, but the detent 119D is held in frictional engagement within either of the recesses 95A or 95B by means to be described.

To provide the required friction, the end 80 of the connector element 74 is formed with an axially extending internally threaded bore 80A which receives therethrough an elongated externally threaded screw 120 having a slotted head 122 to receive an adjusting tool or blade (not shown) therein. The other end of the screw 120 extends into the pocket and bears against the free end 119C of the spring 119 to hold the detent means 119D in frictional engagement with a selected one of the recesses A, 95B and to cause the detent means 119D to frictionally engage and drag over the arcuate portion of the peripheral side edge 95 which extends therebetween as the lever 108 is turned about the pin 92.

The adjustment of the screw relative to the end 119C is such, preferably, that the detent means 119D will enter the selected one of the recesses 95A, 95B crisply and in such a manner that as the lever means 108 pivots through its arc of movement the user will feel a drag of the detent means 119D as the detent means 119]) tracks the arcuate peripheral portion of the edge 95 between the two above-described recesses. This will provide the user of the aid with a sense of security as the walking aid is employed.

The upper frusto-conical end 80 is reduced in diameter to provide an annular abutment shoulder 126. As is seen in FIGURE 2 of the drawings, one end 128 of a conventional arcuately shaped handle 130 telescopes over the reduced end and seats against the annular shoulder 126. The handle 130 is of conventional construction and is here shown as being provided with an external cover 132 formed of any suitable friction material such as, for example, of rubber or similar plastics. The aforementioned end 128 of the handle 130 and the adjacent portions of the cover 132 are fixedly secured on the reduced portion of the upper end 80 by ferrule 134 and one or more set screws 136 (see FIGURE 1).

From the foregoing description of the component elements of this embodiment of the invention, the operation of the device is deemed to be self evident. However, and for the purpose of clarity, a brief description thereof follows.

In FIGURES 1 and 2, the spikes 48 have been shown in their extended operative position for engagement against a slippery surface such as ice covered ground indicated by reference letter G. In this position the shafts 70 and 36 have been moved to their lowermost positions forcing the carrier plug 40 to move to its lowermost position within the chamber 28. The shaft 70 is eccentrically mounted on the disk 94 by its pin 106 and is slightly flexed, to the right as viewed in FIGURE 2, within the main body portion 12 of the cane 10. The enlarged head 110 of the actuating lever 108 is disposed immediately below the overhanging handle 130 and is positioned in such a manner as to conveniently receive the operators index finger through the opening 112. In this position, the cane user may exert an upward pull on the lever 108 to maintain the spikes 48 in their extended operative positions or, optionally, he may rely on the releasable engagement of the detent 119D within the recess 95A. Once these spikes 48 have penetrated the ground G, the user may walk with a sense of security including the making of turns on slippery ground surfaces. In making such turns, the main body portion 12, the connector element 74 and the handle 130 all turn relative to the fitting 18, the carrier plug 38, the spikes 48, and the ground-engaging cap 60, all of the latter remaining stationary.

Under fair weather conditions, the extended ends of the spikes 48 are withdrawn within the end closure wall 64 in order that the ground-engaging cap 60 may be utilized in the conventional manner. The retraction of the spikes 48 is accomplished by turning the lever 108 clockwise, reference being had to FIGURE 2 of the drawings, and this effects a rotation of the disk 48 which, in turn, raises the position of the pivot pin 106. As the pivot pin 106 raises, the shafts 36 and 60 are drawn upwardly in the main body portion 12, and this causes the carrier plug 38 to be withdrawn into the chamber 28 in a direction towards the end wall 30. In effecting the retraction of the spikes 48, the shaft 70 will flex slightly to the left, reference again being made to FIGURE 2, and when the lever means 108 has completed its downward pivotal movement, the detent means 119D will enter the recess 95B to releasably secure the shafts 36, 70 and the connected spikes 48 in their respective raised and retracted positions. In this position of the spikes 48, the main body portion 12 is still free to rotate relative to the fitting 18.

The effective length of the shafts 36, 70 may be easily changed to obtain the desired length of extension of the spikes or ground-engaging elements 48 by backing off the nut 72 from the adjacent end of the shaft 36 and threading the threaded lower end 68 of the shaft 70 into or out of the adjacent upper end of the shaft 36, after which the nut 72 is turned to jam and lock against the adjacent end of the shaft 36.

FIGURES 5 to 8, inclusive, illustrate a second embodiment of this invention wherein the inventive concept is carried over to walking aids in the nature of crutches. In this embodiment of the invention the crutch here bears the general reference numeral 200 and elements of this embodiment of the invention having counterparts in the first embodiment herein described above carry the same reference numerals but to which has been added a prime mark in order to provide for differentiation between the elements of the two embodiments. It should here be observed that with the exception of the actuating means for the crutch, the structure of the second embodiment is substantially identical to the structure of the first one thereof.

The crutch 200 is seen to comprise a pair of elongated substantially hollow cylindrical side frame members 202, 204 having their respective upper ends disposed in substantially laterally spaced and parallel relationship relative to one another. The upper ends of the side frame members 202, 204 are connected together by the usual shoulder bar 206, and a conventional handle piece 208 is connected to the side frame members 202, 204 intermediate their respective opposed ends as by the usual means 210. The lower ends 202A, 204A of the side frame members 202, 204 are bent to converge inwardly towards one another and, adjacent their outer terminal ends 202B, 204B, the side frame members 202, 204 are flattened and bent to fit snugly against the exterior side of the main body portion 12 of the anti-skid attachment. The terminal ends 202B, 204B are secured by screws or other conventional devices 212 to the main body portion 12 intermediate the ends thereof. The upper end of the main body portion 12 may, optionally, be provided with a closure cap 214, but if the cap 214 is provided it will be understood that the same is formed with a transversely extending slot (not shown) in order to provide the shaft 36' with freedom of movement to serve the function described above.

Fixedly connected to the side frame members 202, 204, at the opposed sides thereof, is a pair of brackets 216, 218.

The brackets 216, 218 extend parallel to one another in laterally spaced relationship and are connected to the side frame members 202, 204 by conventional means 220. As is seen in FIGURE 5, the brackets 216, 218 are positioned adjacent to but spaced from the handle means 208.

Reference numeral 222 indicates an elongated cylindrical shaft having one of its ends journaled for rotation in a suitable opening 224 formed in the bracket 218, and the other end of the shaft 222 is threaded for threaded engagement within an internally threaded collar 228 secured in the bracket 216 substantially centrally thereof. A cylindrical disk 94 is mounted for rotation on the shaft 222, and its bore 232 which receives the shaft 222 therethrough is counterbored as at 234. A retaining pin 236 extends transversely through the shaft 222 and has diametrically opposed ends rotatable within the counterbore 234 and immediately adjacent the inner side of the bracket 218. The aforementioned one end of the shaft 222 has a manually operable knob 238 fixedly secured thereon.

The disk 94' is formed with a substantially U-shaped slot 96 having side walls 98, 100 which support the opposed ends of a pivot pin 106. As in the previous embodiment of this invention, the slot 96 has a bight 102' at the inner end thereof and disposed substantially on a cord of the disk 94 and the bight 96 is provided with an inwardly extending socket 104' which opens towards the pin 106'.

A shaft 70 has its threaded end 68' threadedly connected to the upper end of the shaft 36, all as described above, and a lock nut 72' is mounted on the threaded end 68' to cooperate with the shaft 36' in holding the shafts 36 and 70' in axially adjusted relation. As is seen in FIGURES 6 and 8, the pivot pin 106' extends diametrically through the upper end of the shaft 70' to connect the shaft 70 to the disk 94'.

Reference numeral 108 denotes a digital operated actuating lever which, in this instance, is annular in configuration. The lever 108 includes a substantially cylindrical side wall 240 from which laterally projects a boss 242, and from the boss 242 projects an elongated threaded shank 116 which is threadedly engaged Within the tapped opening 118 formed in the disk 94.

With the elements of the anti-skid assembly constructed as described above and in their respective positions illustrated in FIGURES 5 to 8, inclusive, the spikes 48' are in their extended positions. The lever 108' is in its right-hand position as viewed in FIGURES 5 and 6, and the knob 238 has been threaded within the collar 228 to fixedly clamp the disk 94' between the brackets 216, 218. This clamping action will secure the disk 94' against movement to assure the user of the crutch 200 of the constant extension of the spikes 48'. Now, however, should the user of the crutch 200 desire to retract the spikes 48', it is only necessary for him to first back off the knob 238 to release the clamping action of the brackets 216, 218 whereby the user may insert a finger in the cylindrical side wall 240 and draw the lever 108' in a pivotal movement to the left as viewed in FIGURES 5 and 6. As this movement takes place, the disk 94 rotates in a counterclockwise direction thereby causing the pin 106 to raise, drawing with it the shafts 36, 70' and the spikes 48', all in the manner as described above. Thereafter, the user may, optionally, tighten the knob 238 to again clamp the disk 94 between the brackets 216, 218.

With the above-described construction, it is obvious that the user may secure the spikes 48 in any extended adjusted relationship relative to the cap 60 and may secure the same in their adjusted positions by clamping the disk 94' between the brackets 216, 218.

The socket 104' receives the upper end of the shaft 70 when the spikes 48 are in their fully extended positions, and the slot 96' receives the upper end portions of the shaft 70' in other adjusted positions thereof.

What is claimed is:

1. An anti-skid attachment for the ground-engaging end of a walking aid comprising an elongated hollow tubular member including a main body portion having a pair of opposed ends;

-a plurality of elongated ground-engaging members;

means mounting said ground-engaging members on said main body portion adjacent one end thereof for reciprocable axial movement towards and away from said one end and for relative rotation about the longitudinal axis of said main body portion; and

means operatively connected on said ground-engaging members and extending axially of said main body portion to effect said reciprocable movement of said ground-engaging members upon actuation of said means.

2. An attachment as defined in claim 1 and a fitting disposed within said main body portion and having an end projecting beyond said one end thereof, means connecting said fitting on said main body portion for rotation about the longitudinal axis of the latter, said fitting having a chamber formed in said projecting end;

said mounting means including a carrier plug mounted for reciprocation and rotation in said chamber, said rotation being relative to the longitudinal axis of said main body portion;

said ground-engaging members having opposed ends with one of their respective ends connected on said carrier plug; and

said operable means being connected on the carrier plug.

3. An attachment as defined in claim 1 and an elongated fitting having a neck at one end thereof and an elongated substantially hollow housing at an opposed end, said neck being rotatably secured in one end of said main body portion with said housing projecting away therefrom, said neck and housing being rotatable about the longitudinal axis of said main body portion;

said mounting means comprising a carrier plug mounted for reciprocation and rotation within said housing and with respect to the longitudinal axis thereof;

said ground-engaging members comprising spikes having one of their respective ends fixedly connected on said carrier plug with their other respective ends projecting away therefrom for extension and retraction from and inwardly of said housing; and

said operable means including shaft means disposed within said main body portion, said shaft means extending axially of said main body portion and having an end extending through said neck into said housing :for connection with said carrier plug and an opposed end projecting beyond the other end of said main body portion for manual actuation by the user of said aid.

4. An attachment as defined in claim- 1 wherein said main body portion is cylindrical in configuration;

an elongated substantially cylindrical fitting having a cylindrical neck at one end and a substantially hollow cylindrical housing opening outwardly of the opposed end thereof, said neck 'being disposed within said main body portion at said one end thereof with said housing projecting away therefrom;

means securing said neck within said main body portion for rotation about the longitudinal axis of the latter;

said mounting means comprising a substantially cylindrical carrier plug mounted in said housing for reciprocation and rotation relative to the longitudinal laXiS of said housing;

said ground-engaging members comprising elongated spikes having one of their respective ends fixedly connected on said carrier plug with their respective other ends extending in the direction of the open end of said housing;

said operable means comprising an elongated sha'ft having one end mounted for reciprocation axially within said neck and extending into said housing, means connecting said carrier plug on said one end of said shaft for reciprocation therewith and for rotation about its longitudinal axis;

the other end of said shaft extending through the other end of said main body portion;

said operable means further including lever means pivotally supported on said tubular member adjacent said other end of said main body portion, and

means pivotally connecting one end of said lever with said other end of said shaft and with an opposed end of said lever means projecting laterally beyond said tubular member for manual actuation by the user.

5. An anti-skid device as defined in claim 4 and an elongated connector element having opposed ends with one end thereof being fixedly connected on said other end of said main body portion, said connector element having a pocket formed therein opening in a side thereof and said pocket being in open communication with the other end of said main body portion to receive the other end of said shaft therein;

said lever means comprising a disk pivotally supported in said pocket;

means pivotally connecting said other end of said shaft on said disk in 'ofi-set relationship relative to its pivotal axis;

a digitally engageable lever projecting radially from said disk for manual operation to turn said disk to effect reciprocation of said shaft; and

handle means fixedly connected on the other end of said connector element.

6. An anti-skid attachment as defined in claim 5 and an end wall closing the open end of said housing, said end wall having openings extending transversely therethrough to reciprocably receive and guide said spikes therein;

a cap formed of a flexible anti-skid material, said cap embracing said housing and having an end closure wall superimposed against said end wall of said housing; and

said other ends of said spikes in their extended positions projecting beyond said end closure wall and in their retracted positions being withdrawn into said end closure wall.

7. An anti-skid device as defined in claim 5 and means disposed in said pocket and connected on said connector element and cooperating with said disk to releasably secure said disk in a plurality of adjusted positions.

8. An anti-skid attachment as defined in claim 3 and a pair of elongated side frame members having first adjacent laterally spaced and substantially parallel end portions and opposed converging second end portions;

a substantially rigid shoulder engageable bar connecting the terminal ends of said first end portions;

handle means extending between and connected to said first end portions adjacent the inner ends thereof;

said converging ends engaging said main body portion on opposed sides thereof and means fixedly connecting said converging ends thereon with said one end of said main body portion projecting therebeyond and with the other end of said main body portion projecting in the direction of said handle means;

a pair of laterally spaced confronting brackets connected on and extending between said side frame members intermediate said handle means and said other end of said main body portion; and

said operable means includes lever means pivotally supported between said brackets and including a manually actuatable handle at one end of said lever means, and means pivotally connecting the other end of said shaft on said lever means.

9. An attachment was defined in claim 7 wherein said lever means comprises a disk having said manually 1,304,978

lactuatable handle projecting radially from the cir- 2,437,076 cumferential edge thereof; and 2,501,890

means'coacting with said brackets to clamp said disk in 2,667,885

a preselected position of its pivotal movement and 2,682,275

thereby to secure said shaft against reeiprocation. 2,856,943-

I References Cited UNITED STATES PATENTS 5/1889 Remillard 13659 X 10 4 Merrold 135--58 X Clemens Q. 135-59 X Desso et a1. 13558 X Prete 135--59 Eyrich 13553 Sparlin 135-53 Stark 135-59 IiETER M. CAUN, Primary Examiner.

US. Cl. X.R. 

